[PATCH 8/N] Fix memory leak in tree-vectorizer.h

[Martin LiÅka <mliska at suse dot cz>]

Hello.

The patch removes memory leaks that are caused by overwriting an existing
item in stmt_vec_info_vec (in set_vinfo_for_stmt). My first attempt was to call
free_stmt_vec_info for old entries that are overwritten, but it caused double frees
as there are some references between stmt_vec_infos.

So that I've decided to allocate all stmt_vec_info structures from a memory pool, which
is released in free_stmt_vec_info_vec routine. Replacing 'vec' (used for simd_clone_info and same_align_regs) to 'auto_vec'
helps to reduce another leaks. To be honest, the solution is not ideal as destructor
of there auto_vec is not called, however with the patch applied, there is just a single memory leak
in the whole test-suite related to tree-vect-stmts.c (which is unrelated to these vectors).

Patch can bootstrap and survives regression tests on x86_64-unknown-linux-gnu.

Ready for trunk?
Martin

>From a2f09db0c4fe3920c744ccc77cf5e28b2a7df458 Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Wed, 2 Dec 2015 12:59:00 +0100
Subject: [PATCH 1/2] Fix memory leak in tree-vectorizer.h

gcc/ChangeLog:

2015-12-07  Martin Liska  <mliska@suse.cz>

	* tree-loop-distribution.c: Include alloc-pool.h.
	* tree-parloops.c: Likewise.
	* tree-ssa-loop-ivopts.c: Likewise.
	* tree-ssa-loop-manip.c: Likewise.
	* tree-ssa-loop.c: Likewise.
	* tree-vect-data-refs.c: Likewise.
	* tree-vect-loop-manip.c: Likewise.
	* tree-vect-loop.c: Likewise.
	* tree-vect-patterns.c: Likewise.
	* tree-vect-slp.c: Likewise.
	* tree-vect-stmts.c (vectorizable_simd_clone_call): Do not
	release arginfo.
	(new_stmt_vec_info): Allocate stmt_vec_info from a newly added
	pool allocator.
	(free_stmt_vec_info_vec): Release the pool.
	(free_stmt_vec_info): Remove an entry from the memory pool.
	* tree-vectorizer.c (stmt_vec_info_pool): Declare the memory
	pool.
	* tree-vectorizer.h (struct _stmt_vec_info): Replace vec with
	auto_vec and provide default contructor.
---
 gcc/tree-loop-distribution.c |  1 +
 gcc/tree-parloops.c          |  1 +
 gcc/tree-ssa-loop-ivopts.c   |  1 +
 gcc/tree-ssa-loop-manip.c    |  1 +
 gcc/tree-ssa-loop.c          |  1 +
 gcc/tree-vect-data-refs.c    |  1 +
 gcc/tree-vect-loop-manip.c   |  1 +
 gcc/tree-vect-loop.c         |  1 +
 gcc/tree-vect-patterns.c     |  1 +
 gcc/tree-vect-slp.c          |  1 +
 gcc/tree-vect-stmts.c        | 27 ++++++++-------------------
 gcc/tree-vectorizer.c        |  4 ++++
 gcc/tree-vectorizer.h        | 23 +++++++++++++++++++----
 13 files changed, 41 insertions(+), 23 deletions(-)

diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c
index a1936f0..637d8dd 100644
--- a/gcc/tree-loop-distribution.c
+++ b/gcc/tree-loop-distribution.c
@@ -63,6 +63,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa.h"
 #include "cfgloop.h"
 #include "tree-scalar-evolution.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 
 
diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c
index 9b564ca..a1085c1 100644
--- a/gcc/tree-parloops.c
+++ b/gcc/tree-parloops.c
@@ -46,6 +46,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "cfgloop.h"
 #include "tree-scalar-evolution.h"
 #include "langhooks.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 #include "tree-hasher.h"
 #include "tree-parloops.h"
diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index d7a0e9e..5204d13 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -101,6 +101,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-propagate.h"
 #include "tree-ssa-address.h"
 #include "builtins.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 
 /* FIXME: Expressions are expanded to RTL in this pass to determine the
diff --git a/gcc/tree-ssa-loop-manip.c b/gcc/tree-ssa-loop-manip.c
index b614412..f1f9866 100644
--- a/gcc/tree-ssa-loop-manip.c
+++ b/gcc/tree-ssa-loop-manip.c
@@ -39,6 +39,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-loop.h"
 #include "tree-into-ssa.h"
 #include "tree-ssa.h"
+#include "alloc-pool.h"
 #include "cfgloop.h"
 #include "tree-scalar-evolution.h"
 #include "params.h"
diff --git a/gcc/tree-ssa-loop.c b/gcc/tree-ssa-loop.c
index cf7d94e..8dab786 100644
--- a/gcc/tree-ssa-loop.c
+++ b/gcc/tree-ssa-loop.c
@@ -34,6 +34,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "cfgloop.h"
 #include "tree-inline.h"
 #include "tree-scalar-evolution.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 #include "omp-low.h"
 
diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c
index 8810af1..e39c804 100644
--- a/gcc/tree-vect-data-refs.c
+++ b/gcc/tree-vect-data-refs.c
@@ -45,6 +45,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-loop.h"
 #include "cfgloop.h"
 #include "tree-scalar-evolution.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 #include "expr.h"
 #include "builtins.h"
diff --git a/gcc/tree-vect-loop-manip.c b/gcc/tree-vect-loop-manip.c
index 226b88f..bac5763 100644
--- a/gcc/tree-vect-loop-manip.c
+++ b/gcc/tree-vect-loop-manip.c
@@ -39,6 +39,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa.h"
 #include "cfgloop.h"
 #include "tree-scalar-evolution.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 
 /*************************************************************************
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index ee32166..4914e73 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -44,6 +44,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "cfgloop.h"
 #include "params.h"
 #include "tree-scalar-evolution.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 #include "gimple-fold.h"
 #include "cgraph.h"
diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c
index 4b225fb..d5549b2 100644
--- a/gcc/tree-vect-patterns.c
+++ b/gcc/tree-vect-patterns.c
@@ -36,6 +36,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "gimplify.h"
 #include "gimple-iterator.h"
 #include "cfgloop.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 #include "dumpfile.h"
 #include "builtins.h"
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index b893682..8df6343 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -37,6 +37,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "stor-layout.h"
 #include "gimple-iterator.h"
 #include "cfgloop.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 #include "langhooks.h"
 #include "gimple-walk.h"
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 9f11652..b5b2572 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -45,6 +45,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "cfgloop.h"
 #include "tree-ssa-loop.h"
 #include "tree-scalar-evolution.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 #include "builtins.h"
 #include "internal-fn.h"
@@ -2788,7 +2789,7 @@ vectorizable_simd_clone_call (gimple *stmt, gimple_stmt_iterator *gsi,
   gimple *def_stmt;
   gimple *new_stmt = NULL;
   int ncopies, j;
-  vec<simd_call_arg_info> arginfo = vNULL;
+  auto_vec<simd_call_arg_info> arginfo;
   vec<tree> vargs = vNULL;
   size_t i, nargs;
   tree lhs, rtype, ratype;
@@ -2854,7 +2855,6 @@ vectorizable_simd_clone_call (gimple *stmt, gimple_stmt_iterator *gsi,
 	  if (dump_enabled_p ())
 	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
 			     "use not simple.\n");
-	  arginfo.release ();
 	  return false;
 	}
 
@@ -3010,10 +3010,7 @@ vectorizable_simd_clone_call (gimple *stmt, gimple_stmt_iterator *gsi,
       }
 
   if (bestn == NULL)
-    {
-      arginfo.release ();
-      return false;
-    }
+    return false;
 
   for (i = 0; i < nargs; i++)
     if ((arginfo[i].dt == vect_constant_def
@@ -3026,10 +3023,7 @@ vectorizable_simd_clone_call (gimple *stmt, gimple_stmt_iterator *gsi,
 	if (arginfo[i].vectype == NULL
 	    || (TYPE_VECTOR_SUBPARTS (arginfo[i].vectype)
 		> bestn->simdclone->simdlen))
-	  {
-	    arginfo.release ();
-	    return false;
-	  }
+	  return false;
       }
 
   fndecl = bestn->decl;
@@ -3041,10 +3035,7 @@ vectorizable_simd_clone_call (gimple *stmt, gimple_stmt_iterator *gsi,
      performed using SIMD instructions.  */
   if ((loop == NULL || (unsigned) loop->safelen < nunits)
       && gimple_vuse (stmt))
-    {
-      arginfo.release ();
-      return false;
-    }
+    return false;
 
   /* Sanity check: make sure that at least one copy of the vectorized stmt
      needs to be generated.  */
@@ -3073,7 +3064,6 @@ vectorizable_simd_clone_call (gimple *stmt, gimple_stmt_iterator *gsi,
 	dump_printf_loc (MSG_NOTE, vect_location,
 			 "=== vectorizable_simd_clone_call ===\n");
 /*      vect_model_simple_cost (stmt_info, ncopies, dt, NULL, NULL); */
-      arginfo.release ();
       return true;
     }
 
@@ -8333,7 +8323,7 @@ stmt_vec_info
 new_stmt_vec_info (gimple *stmt, vec_info *vinfo)
 {
   stmt_vec_info res;
-  res = (stmt_vec_info) xcalloc (1, sizeof (struct _stmt_vec_info));
+  res = stmt_vec_info_pool.allocate ();
 
   STMT_VINFO_TYPE (res) = undef_vec_info_type;
   STMT_VINFO_STMT (res) = stmt;
@@ -8396,6 +8386,7 @@ free_stmt_vec_info_vec (void)
       free_stmt_vec_info (STMT_VINFO_STMT (info));
   gcc_assert (stmt_vec_info_vec.exists ());
   stmt_vec_info_vec.release ();
+  stmt_vec_info_pool.release ();
 }
 
 
@@ -8442,10 +8433,8 @@ free_stmt_vec_info (gimple *stmt)
 	}
     }
 
-  STMT_VINFO_SAME_ALIGN_REFS (stmt_info).release ();
-  STMT_VINFO_SIMD_CLONE_INFO (stmt_info).release ();
+  stmt_vec_info_pool.remove (stmt_info);
   set_vinfo_for_stmt (stmt, NULL);
-  free (stmt_info);
 }
 
 
diff --git a/gcc/tree-vectorizer.c b/gcc/tree-vectorizer.c
index b721c56..e9f5692 100644
--- a/gcc/tree-vectorizer.c
+++ b/gcc/tree-vectorizer.c
@@ -71,6 +71,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-loop-manip.h"
 #include "tree-cfg.h"
 #include "cfgloop.h"
+#include "alloc-pool.h"
 #include "tree-vectorizer.h"
 #include "tree-ssa-propagate.h"
 #include "dbgcnt.h"
@@ -82,6 +83,9 @@ source_location vect_location;
 
 /* Vector mapping GIMPLE stmt to stmt_vec_info. */
 vec<stmt_vec_info> stmt_vec_info_vec;
+
+object_allocator <_stmt_vec_info> stmt_vec_info_pool ("STMT vec info");
+
 
 /* For mapping simduid to vectorization factor.  */
 
diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
index 327f08d..d7f4de4 100644
--- a/gcc/tree-vectorizer.h
+++ b/gcc/tree-vectorizer.h
@@ -478,7 +478,20 @@ enum slp_vect_type {
 
 typedef struct data_reference *dr_p;
 
-typedef struct _stmt_vec_info {
+struct _stmt_vec_info
+{
+  _stmt_vec_info (): type ((enum stmt_vec_info_type) 0), live (false),
+  in_pattern_p (false), stmt (NULL), vinfo (0), vectype (NULL_TREE),
+  vectorized_stmt (NULL), data_ref_info (0), dr_base_address (NULL_TREE),
+  dr_init (NULL_TREE), dr_offset (NULL_TREE), dr_step (NULL_TREE),
+  dr_aligned_to (NULL_TREE), loop_phi_evolution_base_unchanged (NULL_TREE),
+  loop_phi_evolution_part (NULL_TREE), related_stmt (NULL), pattern_def_seq (0),
+  same_align_refs (0), simd_clone_info (0), def_type ((enum vect_def_type) 0),
+  slp_type ((enum slp_vect_type) 0), first_element (NULL), next_element (NULL),
+  same_dr_stmt (NULL), size (0), store_count (0), gap (0), min_neg_dist (0),
+  relevant ((enum vect_relevant) 0), vectorizable (false),
+  gather_scatter_p (false), strided_p (false), simd_lane_access_p (false),
+  v_reduc_type ((enum vect_reduction_type) 0) {}
 
   enum stmt_vec_info_type type;
 
@@ -543,12 +556,12 @@ typedef struct _stmt_vec_info {
 
   /* List of datarefs that are known to have the same alignment as the dataref
      of this stmt.  */
-  vec<dr_p> same_align_refs;
+  auto_vec<dr_p> same_align_refs;
 
   /* Selected SIMD clone's function info.  First vector element
      is SIMD clone's function decl, followed by a pair of trees (base + step)
      for linear arguments (pair of NULLs for other arguments).  */
-  vec<tree> simd_clone_info;
+  auto_vec<tree> simd_clone_info;
 
   /* Classify the def of this stmt.  */
   enum vect_def_type def_type;
@@ -597,8 +610,9 @@ typedef struct _stmt_vec_info {
 
   /* For reduction loops, this is the type of reduction.  */
   enum vect_reduction_type v_reduc_type;
+};
 
-} *stmt_vec_info;
+typedef struct _stmt_vec_info *stmt_vec_info;
 
 /* Access Functions.  */
 #define STMT_VINFO_TYPE(S)                 (S)->type
@@ -685,6 +699,7 @@ struct dataref_aux {
 #define MAX_VECTORIZATION_FACTOR 64
 
 extern vec<stmt_vec_info> stmt_vec_info_vec;
+extern object_allocator <_stmt_vec_info> stmt_vec_info_pool;
 
 void init_stmt_vec_info_vec (void);
 void free_stmt_vec_info_vec (void);
-- 
2.6.3